pathwaycom/pathway · error · NotImplementedError

{key}: {repr} not supported.

Error message

{key}: {repr} not supported.

What it means

Every handler in Pathway's SQL translator pops the args it understands from the sqlglot node; before returning, _check_work_done scans node.args for anything left over. Any non-None remaining arg causes NotImplementedError('{key}: {repr} not supported.') naming the unhandled clause. It is Pathway's safety net for query clauses it parses but does not translate.

Source

Thrown at python/pathway/internals/sql/processing.py:649

) -> tuple[table.Table, ContextType]:
    if (alias_field := node.args.pop("alias", None)) is not None:
        alias = _run(alias_field, context)
        assert isinstance(alias, str)
        context = context.copy()
        tab = tab.copy()
        context[alias] = tab
    return tab, context


def _check_work_done(node: sql_expr.Expression) -> None:
    for key, obj in node.args.items():
        if obj is None:
            continue
        try:
            repr = obj.sql()
        except AttributeError:
            repr = str(obj)
        raise NotImplementedError(f"{key}: {repr} not supported.")

View on GitHub (pinned to fa2f74a464)

Solutions

1. Use the {key} in the message to identify which clause is unhandled, and remove or rewrite that clause
2. Split the query: run the supported part in pw.sql and do ordering/limiting/reshaping with Pathway native operations
3. Check the Pathway SQL docs for supported clauses; if a sqlglot upgrade shifted parsing, pin the version Pathway was tested with

Example fix

-- before (ORDER BY left unconsumed in this position)
SELECT k FROM t UNION SELECT k FROM u ORDER BY k;

# after: sort outside SQL
import pathway as pw
t = pw.sql("SELECT k FROM t UNION SELECT k FROM u")
sorted_t = t.sort(pw.this.k)

try:
    tab = pw.sql(query)
except NotImplementedError as e:
    logUnsupportedClause(str(e))  # record which {key} clause failed, feed back to query author
    raise

When it happens

Trigger: pw.sql with clauses the specific handler doesn't consume: e.g. ORDER BY in contexts Pathway ignores, WITH (CTE) attachments on particular nodes, HAVING in unsupported positions, FETCH/ OFFSET variants, hints, or dialect-specific qualifiers on a sub-node.

Common situations: Complex analytical SQL ported from another engine; sqlglot version changes that move a clause into an arg position Pathway's handler doesn't pop; queries that parse fine but use a corner-of-the-grammar feature.

Related errors

• {node.sql()} not supported.
• PIVOTS not supported
• parsing {query} failed
• Correlated subqueries not supported.
• Currently, tantivy bm25 index is supported only in the as-of

AI-assisted analysis of pathwaycom/pathway@fa2f74a464 (2026-08-15). Data as JSON: /api/errors/30cafc4b9e2a4281. Report an issue: GitHub.